1. MUSCLES MOVE! Muscle work requires energy! Muscles need oxygen to work. If they don’t get enough oxygen when working, they will produce muscle fatigue from lactic acid and will ache or stop working completely. The energy comes from oxygen and glucose from the carbohydrates you eat. To release energy the glucose must combine with oxygen from red blood cells. Muscles cramp when there is not enough oxygen and lactic acid builds up. Inside muscles ATP is like a battery that stores energy. Muscles work if they have a constant supply of ATP provided by respiration. Aerobic = food + oxygen = ATP. If you exercise intensely and the heart can’t keep up then the anaerobic system takes over and ATP is produced without oxygen and also produces the poison lactic acid. You need protein for healthy muscles. Aerobic exercise increases oxygen in the blood and strengthens the heart. The more you exercise, the more food and oxygen you need. The more you use muscles, the stronger they grow. Without exercise, healthy nourishment and enough oxygen muscles become smaller and weaker. To strengthen muscles you must work against a stronger resistance than used to and increase as muscle training continues. Exercise doesn’t increase the number of muscle cells but increases the size of the existing cells. To develop bigger muscles the individual muscle filaments grow in thickness 24-48 hours later.
Muscles have the only kind of tissue that can contract getting shorter and thicker. Put your thumbs in your ears and you can hear the rumbling sound of your muscles contracting! We have 656 muscles in our body. More than 200 operate when we take a step. They are controlled by the central nervous system through nerve impulses from our brain. If your nervous system weren’t so efficient, you might be socking yourself in the face instead of scratching your nose!
Muscles are voluntary as skeletal muscles or involuntary as organs. Muscles are mostly protein – meat on the bones – flesh. When we eat meat we are eating muscle tissue. There are red and white muscle cells mixed together. Red cells work longer but white cells are stronger. This is why there is white meat and red meat.
Muscles are attached to our bones by tough inelastic tendons. We can see tendons on the back of the hand. You can feel one of the biggest tendons, the achilles at the back of your foot at the heal. Bones are attached to bones by ligaments and joints are oiled by synovial fluid. Cartilage acts as a shock absorber. It is cartilage that grows into bone.
3 kinds of muscle:
1. Striped Skeletal Muscles – Are voluntary muscles. We can control these muscles at will. Most are attached to bone and move us. The muscles can’t push but work in pairs. One relaxes and the other contracts. one muscle gets long and the other contracts to shorten. Our reflex action is involuntary and comes from the spinal chord.
2. Smooth Muscles are responsible for the movements inside of us – our guts and organs. We cannot control the digestive or circulatory system, nor the diaphragm, muscle of the iris in the eye, or the muscle of each hair when we get goose bumps. When we are hungry our stomach muscle contracts and if there is air in the stomach it growls for food!
3. Cardiac Muscle makes up our heart and is our strongest involuntary muscle. We cannot control it and it never stops working till we die. The heart is a pump that feeds oxygen and nutrition to our body.
Muscles Matter – The Benefits of Muscles:
1. Move parts of our body allowing many kinds of activity such as swimming or painting
2. The heart pumps blood through our body to feed it oxygen and nutrition to keep us alive and healthy
3. Protect inside organs
4. Stabalizes the spine of the skeletal system.
5. Shape us – our face and whole body
6. Allow us to breathe, eat, digest food, talk, sing, whistle, see,
7. Allow us to manipulate things
8. Keep us warm with a shiver
The tongue is your most flexible and dangerous muscle. Our smallest muscle is in the ear. The largest in in our rear – the gluteous maximus of our derriere. Our strongest is the jaw masseter muscle we use to bite, chew and talk. The most active muscles are the eye muscles. Takes more muscles and energy to frown than to smile!
In multiple schlerosis a layer of fat is absent from muscles and they can’t transmit nerve messages properly. Muscular dystrophy is when muscles waste away. Muscles can become paralized from brain damage. A strained muscle is one that has been stretched too much.
Be a body scientist and test your reaction time catching a ruler, check your pulse, listen to your heart, listen to your muscles contract, check knee reflex, lung capacity, nail growth, and get outside and exercise!